Self-threading needle



July 24, 1951 D M 2,561,502

SELF-THREADING NEEDLE Filed Feb. 21, 1947 INVENTOR. Charles W. Diemer Patented July 24, 1951 UNITED STATES PATENT OFFICE Charles W. Diemer, Upper Darby, Pa; Application February 21, 1947;Serial No. 729,956

I i i .1

; My inyention. relates to sewing needle and moreparticularly to an im-provedself threading needle constructionsuited especially for sewing machines,

I have .found that ordinary self threading needies are unsuitable. foruse withsewing machines for several reasons. In the first place, the construction of the'needle must be suificiently strong to 'withstand machine operation as distinguished from handoperation. In the second place, the self .-.threading sewing machine needle must be capable of .being. inserted through the material in one direction and withdrawn from the material in the. opposite direction without snagging or in anyway catching on the goods. Hand needles on the contrary are always inserted throughthe goods in only one direction and as a result many so-called self threading designs as applied to hand needles are entirely uselessfor reversible operation in a sewing machine. Furthermore, the eye of a machine needle of necessity must be at or near the pointof the needle which is of'course the Weakest portion both because it is farthest from the supporting element and also because the needle pointmust beof much smaller diameter than the shank with consequent. less steel available for strength.

additional feature of my constructionresides in the fact that the conventional sewing machine needle is readily modified, in accordance with the invention, to form a self threading needle and the operation is adapted to mass production requiring no complicated equipment. In this connection, the simplicity and ease of manufacture of my needle is strikingly apparent when compared with the prior art constructions such as the following United States patents: 622,080 to Roszell, 913,648 to Reeder and 1,134,001 to Olney.

The term fself threading? as used herein refers to a needlewhich can be threaded without inserting the end of the thread through the eye of the needle, and the above cited patents are examples of such construction:

, A- primary-object; thereforaiof the: invention .is to provide a sewing needle having an eye adapted to carry the thread, one side of the eye being open, and the opposite side being resilient.

A further object of the invention is to provide asewing machine needle having a conventional eye a portion of which eye is located within the point portion of the needle, the eye having two lateral sides, one side of the eyebeing ground away arcuately to provide s slotg-the other side comprising a continuous resilient wall the lower porticin of which includes a part of said point'por- 2 Claims. (01. 112-224.).

tion, which part being thinner and hence .more readily bendable than the remaining parts of said wall, provides access of the thread through the slot, and supplying rigidity when'pressure is err-- erted against the pointof the needle to close the slot to the eye.-

Further objects will be apparent from the specifications and. drawings in which:

Fig. 1 is a front elevation of a sewing machine needle constructed in accordance with the invention,

Fig. 2 is a side elevation of the structure shown in Fig. 1,

Fig. "3 is an enlarged detail of the needle point.

and illustrates the needle eye in unstressed condition,

Fig. 4 illustrates the method of inserting a thread intothe. eye of l the needle without the necessity of utilizing an end of the thread,

Fig. 5 illustrates the slightly stressed position of the needle assumed during the sewing opera-.

tion and in which the thread aperture is closed to provide. support for theineedle point.

Fig- 6 illustrates a grinding Wheel as applied to.

a conventional needle to form the self threading; feature, and

Fig.7 is a view along the plane 'l'! of. Fig. 6

illustrating the method of grinding the arcuate. slot in the: eye and shows how the grinding wheel is bothhrotated and revolved with respect to the needle or the needle may be rotated on its own axis in either or both directions or the grinder may be revolved with respect to the needle and.

at the same time the needle may be rotated on itsaxis.

Referring more particularly to the drawings, Figs. 1 and 2 illustrate a conventional sewing machine. needle I having an elongated body por-. tion 2 and a shank 3 adapted to be inserted in a sewing machine and retained therein by means of.

thefiattened portion 4 of shank 3. Shank 3 and body 2 of the needleare joined by tapered section 5 which also provides the upper terminus of an elongated slot 6 extending along one side of body 2 from a point I at the tip 8 of the needle to shank.

5. Body portion 2 tapers to form the tip or point 8 and contains therein an elongated or oval eye 9 which extends through the needle at right angles to the flattened portion 4 or" shank 3, which eye is substantially centered within a. concave elliptical recess H] which surrounds one extremity of. the eye 9 and provides thread clearance facilitating the piercing of material by the needle.

.Referring now to Figs. 3-5, the elongated eye has an aperture l I located centrally of theeye and atone side of the shank 2. Slot I i is bounded by shoulders l2 and [3 having curved edges extending laterally around the slot. The opposite side of eye 9 is formed by portion 15 which conn-ects point 8 with shank 2, it being noted that the lower part of portion l5 includes a part of point portion 8 which part is thinner and, hence, more readily bendable than the remaining part of portion l5. When thread T is inserted in slot l I, shoulders'i 2 and i3 are spread apart to spring side [5 in the general position illustrated in Fig. 4. After the thread T is inserted in the hole, side returns to an unstressed position such as shown in Fig. 3 but when the needle is forced through material l6, pressure on the point it of the needle vides ample support for all stress in compression.

Obviously the force required to withdraw the needle from the goods is of a much lower degree and, therefore, there will be insuiiicient stress in tension on portion 15 to cause breakage.

The laterally rounded edges of shoulders l2 and i3 prevent any tendency to snag the material, either when the needle is'entering or being withdrawn from the material, and I have found that good results are obtained when slot 5 i for. the conventional needle is on the order of .006 in width.

Needles having a slotted eye constructed in accordance with the invention are readily fabricated in mass production by means of a circular grinding wheel ll rotatable on shaft 58. The grinding wheel has a central lip i9 adapted to grind the minimum width of slot ii and curved portionsfit and ii on either side of portion l9 adapted to grind the curved shoulders l2 and i3. In order to insure that shoulders i2 and i3 are rounded on all sides, grinding wheel ll is revolved through an are illustrated by the broken line in Fig. 'l and if desired, the needle may also be rotated to achieve the same result depending upon the tooling setup. It will be apparent that the needle may be rotated on its longitudinal axis while the shaft ill of the grinding wheel is maintalned in a stationary position or the needle may be held stationary and the wheel revolved as describedabove or a combination of both motions may be employed. Either the needle or the wheel may be rotated in the same or opposite directions.

It will thus be apparent that I have provided a self threading needle which is efficient, strong and extremely cheap to manufacture in quan-',

tity. The construction may employed on both hand and sewing'machine needles although the advantages when used on the sewing machine type are more striking. The more rapid machine operation causes heating of the needl and this is one of the main reasons why self threading sewing machine needles have proved unsatisfactory in the past since the tendency of the needles to break is greatly increased when they become overheated. A further advantage of my self threading needle when applied to a sewing machine resides in the fact that a sewing machine needle must be illSEiJECl in the machine With the longitudinal slot 5 always in the same position Since the maximum strain on the nee- 4 correctly threads the needle from the front or the back, the fact that slot I I is not in its proper position will immediately give warning that the needie is in backwards. Another important advantage in the construction of the needle lies in the fact that the aperture can be cut in an otherwise finished and tempered needle. No hot working is required.

While certain novel features of the invention are disclosed herein with considerable detail with respect to certain particular forms of the invention, it is not desired to be limited to such details since many changes and modifications may well be made without departure from the spirit of the invention.

Having thus described my invention, I claim:

1. A sewing needle having an elongated shank portion terminating at one end in a point portion, and elongated eye formed in said needle with its major axis extending axially of said needle and with a portion-of said eye located in said point portion, said eye being defined at one side of said needle by a continuous resilient wall the lower portion of which includes a part of said point portion, said part being thinner and hence more readily bendable than the remaining parts of said wall, and the opposite wall defining said eye having a relatively narrow gap formed therein through which a sewing thread may be laterally insertedinto the eye, the thinner part of said continuous resilient wall insuring ready bending of said wall to close the gap in said opposite wall so that the ends of the wall defining said gap are brought into abutting relation to provide support for the point portion when the needle is inserted into a fabric.

2. A sewing needle having an elongated shank portion terminatingat one end in a point portion,

and an oval eye formed in said needle and'substantially centered within a concave elliptical recess formed in the needle, the major axes'of said eye and recess being substantially parallel and extending axially of said needle and portions of said eye and recess being located in said point portion, saideye and recess being defined at one side of said needle by a continuous resilient wall the lower portion of which includes a part of said point portion, said part being thinner'and hence more readily bendable than the remaining parts of said wall, and the opposite wall defining said eye and recess having a relatively narrow gap formed therein through which a sewing thread may be laterally inserted into the eye, the thinner part of said continuous resilient wall insuring ready bending of said wall to close the gap in said opposite wall so that the ends of the walls defining said gap are brought into abutting relation to provide support for the point portion when the needle is inserted into a fabric.

" CHARLES W. DIEMER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENT Italy Oct. 22, 193': 

